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Full-Text Articles in Physical Sciences and Mathematics

Use Of Molecular Logic Gates For The Tuning Of Chemosensor Dynamic Range, Orhan Acikgoz May 2024

Use Of Molecular Logic Gates For The Tuning Of Chemosensor Dynamic Range, Orhan Acikgoz

Undergraduate Honors Theses

The first molecular logic gates were created in the 1990s; integrating such logic gates into fluorescent chemosensors allowed for the detection of different types of ions in solution. In this study, we have developed a new use of molecular logic gates by having two of the same type of binding site. The two binding sites on a fluorophore that both detect Na+ ions led to an increase in the detection limit compared with the chemosensor with a single binding site. Since the two sodium binding sites create an AND logic gate, two sodium ions are needed to generate a …


Mechanisms Of Formation Of Novel Guanine-Guanine Cross-Links As Major End Products During One-Electron Oxidation Of Guanine Derivatives, Evan Dunn May 2023

Mechanisms Of Formation Of Novel Guanine-Guanine Cross-Links As Major End Products During One-Electron Oxidation Of Guanine Derivatives, Evan Dunn

Undergraduate Honors Theses

Guanine (G), as the most oxidizable base in DNA, is the major focus of studies of oxidation damage to DNA. The present thesis reports the first detailed characterization of G dimerization products potentially resulting from recombination of neutral G• radicals. Previous research has discovered a novel type of products of G• dimerization, D1 and D2, formed from one-electron oxidation of G derivatives. However, the mechanism of this dimerization remains elusive. While there appears to be a tautomeric equilibrium between two forms of G•, G(N1-H)• or G(N2-H)•, it remains unclear which intermediate participates in the formation of …


Gas-Phase Proton Affinities For Twenty Of The Proline-Containing Dipeptides, Henry Cardwell May 2022

Gas-Phase Proton Affinities For Twenty Of The Proline-Containing Dipeptides, Henry Cardwell

Undergraduate Honors Theses

Peptide fragmentation plays a crucial role in the analysis of proteins through mass spectrometry-based proteomics. Most proteomics experiments take place in the low-energy regime and are governed by the mobile proton model which predicts random cleavages along the peptide backbone; however, there sometimes arise circumstances where the mobile proton model fails causing sequencing algorithms to misidentify peptides. One such example is noted in the “proline effect” wherein proline-containing peptides preferentially fragment N-terminal. While it has been established that the “proline effect” is due to the rigidity and basicity of the proline N-terminus, a further understanding of the factors influencing the …


Investigating Charge Transfer Complexes In Brown Carbon Aerosols, Brianna Peterson May 2021

Investigating Charge Transfer Complexes In Brown Carbon Aerosols, Brianna Peterson

Undergraduate Honors Theses

Aerosols are suspensions of particles in the air, commonly seen as dust or fog in the atmosphere. Brown carbon is a particular classification of carbonaceous atmospheric aerosol that increases in absorption from the visible to ultraviolet region, making it important for radiative forcing models. Elucidating the structures of brown carbon chromophores has been difficult as brown carbon is a broad category and the chromophore type can change depending on emission source, temperature, humidity, and season. Twisted intramolecular charge transfer (TICT) molecules have been identified as potential brown carbon chromophores. TICT molecules are those that allow charge transfer to occur between …


Computational Study Of Novel Fxbn Spin Trap Analogs With Hydroxyl Radicals, Alexis Harvey May 2020

Computational Study Of Novel Fxbn Spin Trap Analogs With Hydroxyl Radicals, Alexis Harvey

Undergraduate Honors Theses

Free radicals are reactive molecules, which makes them difficult to study. Learning more about free radicals is necessary since they are implicated in many diseases and conditions such as Alzheimer’s disease and aging. Spin traps are molecules that can be used to stabilize free radicals to allow time for the free radicals to be characterized. The purpose of this research was to examine four novel spin traps that combine the properties of existing spin traps to possibly create more effective spin traps. The four novel molecules in question were designed by taking the 4-methylfuroxanyl ring from the α(Z)-(3-methylfuroxan-4-yl)-N-t-butylnitrone spin trap …


Chemically Accurate Calculations Of Rate Constants Of Spin Trap-Hydroxyl Radical Addition Reactions, Hayden B. Short May 2015

Chemically Accurate Calculations Of Rate Constants Of Spin Trap-Hydroxyl Radical Addition Reactions, Hayden B. Short

Undergraduate Honors Theses

The DMPO type spin trap 5,5-Dimethyl-1-pyrroline N-oxide (DMPO) and the exceptionally similar spin trap 2-ethoxycarbonyl-2-methyl-3,4-dihydro-2H-pyrrole-l-oxide (EMPO) are widely studied in computational and theoretical works. This particular study examines the addition reactions that both these molecules undergo with the carcinogenic hydroxyl radical. This work used a relatively new approximation method, called the correlation consistent composite approach or ccCA, for carrying out quantum mechanical calculations to give the free energies of the products and reactants of the reactions. The free energies are to be used to extrapolate the rate constants of the reactions from the Arrhenius equation. Though both the spin traps …


The Effect Of Ph And Counterion On The Size Distribution And Luminescence Lifetime Of Terbium-Doped Lanthanum Nanocrystals, Sarah Baker Dec 2014

The Effect Of Ph And Counterion On The Size Distribution And Luminescence Lifetime Of Terbium-Doped Lanthanum Nanocrystals, Sarah Baker

Undergraduate Honors Theses

In recent years, nanoparticles have been applied to and have gained prevalence in fields such as chemistry, biology, the medical sciences, and biotechnology,and have attracted the attention of medical researchers as potential microscopic drug delivery systems in the human body. In particular, nanoparticles made with the lanthanides have shown themselves to be useful to many biological applications due to their unique luminescent properties. It is crucial to determine optimum synthetic parameters so that nanoparticles are both small enough to pass through the kidneys and also have the ability to attach different functional groups so that they may be relevant to …


Isotropic Oscillator Under A Magnetic And Spatially Varying Electric Field, David L. Frost Mr., Frank Hagelberg Aug 2014

Isotropic Oscillator Under A Magnetic And Spatially Varying Electric Field, David L. Frost Mr., Frank Hagelberg

Undergraduate Honors Theses

We investigate the energy levels of a particle confined in the isotropic oscillator potential with a magnetic and spatially varying electric field. Here we are able to exactly solve the Schrodinger equation, using matrix methods, for the first excited states. To this end we find that the spatial gradient of the electric field acts as a magnetic field in certain circumstances. Here we present the changes in the energy levels as functions of the electric field, and other parameters.


The Analysis Of The Decomposition Of Hydrogen Peroxide Using A Schiff Base Copper Complex By Cyclic Voltammetry, Gavin James Rustin Mr. May 2014

The Analysis Of The Decomposition Of Hydrogen Peroxide Using A Schiff Base Copper Complex By Cyclic Voltammetry, Gavin James Rustin Mr.

Undergraduate Honors Theses

Copper(II) complexes of Schiff bases can be used in the catalysis of hydrogen peroxide to create water and oxygen. The mechanism and the kinetics of this disproportionation reaction by a dimeric copper(II) complex [CuSALAD]2 are studied in this experiment, where SALAD refers to a Schiff Base ligand formed from salicyaldehyde and 1S,2S-D(+)-1-phenyl-2-amino-1,3-propanediol. By using cyclic voltammetry, the oxidation-reduction processes of a reaction may be monitored. The [CuSALAD]­2 is initially reacted with a base such as imidazole to form the catalytic species, and the ratio of the copper(II) complex to the imidazole was found to be 1:4, consistent with …